JP2010272513A - Secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery which can increase output and capacity and can improve reliability for safety. <P>SOLUTION: The secondary battery includes: an electrode assembly including a first electrode plate having a plurality of first protrusions extending from one end thereof and a second electrode plate having a plurality of second protrusions extending from the one end, wherein at least one of the plurality of first protrusions or the plurality of second protrusions includes a planar portion and a curved portion; a case accommodating the electrode assembly; and a collector plate which is connected to at least one of the plurality of first protrusions or the plurality of second protrusions and covers at least the curved portion. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a secondary battery.

  A secondary battery (rechargeable battery) is a battery that can be charged and discharged, unlike a primary battery that cannot be charged. In the case of a low-capacity battery in which one battery cell is packaged in a pack form, a mobile phone In the case of a large-capacity battery in units of battery packs that are used in portable electronic devices such as video cameras and in which several tens of battery packs are connected, they are widely used as power sources for driving motors in hybrid vehicles and the like.

  Secondary batteries are manufactured in various shapes, but typical shapes include a cylindrical shape and a square shape, and a separator that is an insulator is interposed between a strip-shaped positive electrode and a cathode plate, An electrode assembly (or jelly roll) wound up in a vortex is installed in a case, and a cap assembly in which electrode terminals are formed is installed in the case.

  Among secondary batteries, a large-capacity battery has a function of collecting a large amount of current instantaneously on the capacity and output surface, and the anode uncoated portion of the anode plate exposed at both ends of the electrode assembly and the collector plate Electrically connected to each of the cathode uncoated portions of the cathode plate, the current generated in the cathode and cathode plate is induced to the cathode and cathode terminals.

  An object of the present invention is to provide an electrode terminal by including a current collector plate connected to an electrode terminal and connected to a round part of an electrode plain part protruding from an upper part of an electrode assembly having a vertical winding shaft. An object of the present invention is to provide a secondary battery capable of reducing the current path length between the electrode assembly and the internal resistance.

  Another object of the present invention is to directly connect the electrode assembly and the current collector plate without a separate connection tap, thereby reducing the space occupied by the separate connection tap inside the case, and reducing only the reduced space. An object of the present invention is to provide a secondary battery capable of increasing the capacity of the battery by increasing the number of winding turns of the electrode assembly.

  Another object of the present invention is to dispose gas generated from the inside of the electrode assembly by disposing a current collector plate on the upper part of the electrode assembly having a vertical winding shaft and coupling it by laser welding. A secondary battery capable of improving the reliability of the battery safety by ensuring that the discharge area is secured and gas is smoothly discharged from the inside of the electrode assembly to the safety vent located above the electrode assembly. Is to provide.

  In order to achieve the above object, a secondary battery according to the present invention includes a first electrode plate having a plurality of first protrusions extending from one end and a second electrode having a plurality of second protrusions extending from the one end. An electrode assembly, wherein at least one of the plurality of first protrusions or the plurality of second protrusions includes a flat portion and a round portion, and accommodates the electrode assembly And a current collector plate connected to at least one of the plurality of first protrusions or the plurality of second protrusions and covering at least the round part.

  The flat portion extends in the length direction of the electrode assembly, the round portion is located on one side of the terminal end of the electrode assembly from the central axis of the electrode assembly, and the current collector plate is the round plate It can be welded to the part.

  The flat part may have a flat edge perpendicular to the length direction from one side closest to the central axis.

  The flat portion may have a flat edge inclined from the length direction toward a central region of the electrode assembly.

  The current collector plate may include a flat region portion at a position corresponding to the flat portion of the electrode assembly, and a round region portion welded to the round portion of the electrode assembly.

  The current collector plate is a first current collector plate connected to the plurality of first protrusions from a first side of one end of the electrode assembly, and the first side of one end of the electrode assembly. And a second current collector plate connected to the plurality of second protrusions from the second side opposite to the first side.

  The current collector plate may include a groove, and may be welded to the electrode assembly at the groove.

  The groove portion of the current collector plate can press and / or bend at least one of the plurality of first protrusions or the plurality of second protrusions.

  The current collector plate may further include a base portion including the groove portion and a flange portion surrounding the base portion.

  The groove portion of the current collector plate includes a plurality of groove portions extending in the length direction and can be welded to the electrode assembly.

  The groove portion of the current collector plate includes a plurality of groove portions extending in a direction perpendicular to the length direction, and can be welded to the electrode assembly.

  The current collector plate may have at least one opening formed through the groove.

  The at least one opening may include a plurality of slits.

  One end of the electrode assembly may be uncoated with an electrode active material.

  A cap plate for sealing the opening of the case and a cap assembly including a safety vent formed to remove gas from the secondary battery may be further included.

  The current collector plate may be laser welded to at least one of the plurality of first protrusions or the plurality of second protrusions.

  The secondary battery according to the present invention includes a current collector plate coupled to an electrode plain lawood portion protruding from an upper portion of an electrode assembly having a vertical winding shaft, and coupled to an electrode terminal. The current path length between the terminal and the electrode assembly can be reduced, and the internal resistance can be reduced.

  In addition, the secondary battery according to the present invention reduces the space occupied by the separate connection tap inside the case by directly coupling the electrode assembly and the current collector plate without the separate connection tap, and only the reduced space. The capacity of the battery can be increased by increasing the number of winding turns of the electrode assembly.

  In addition, the secondary battery according to the present invention releases a gas generated from the inside of the electrode assembly by arranging a current collector plate on the upper part of the electrode assembly having a vertical winding shaft and coupling it by laser welding. While ensuring the area, the gas can be smoothly discharged from the inside of the electrode assembly to the safety vent located at the top of the electrode assembly, so that the reliability with respect to the safety of the battery can be improved.

1 is a perspective view showing a secondary battery according to an embodiment of the present invention. It is sectional drawing which shows the secondary battery of FIG. FIG. 2 is an exploded perspective view showing a state before the electrode assembly is wound up in the secondary battery of FIG. 1. FIG. 2 is a partially separated perspective view showing an electrode assembly, first and second current collector plates, and first and second electrode terminals in the secondary battery of FIG. 1. FIG. 5 is a perspective view illustrating a state in which the lower surface of the first current collector plate of FIG. 4 is directed upward. It is the perspective view which expanded and showed the "A" part of FIG. It is a perspective view which shows the other example of the electrode assembly of FIG. It is a perspective view which shows the other example of the electrode assembly of FIG. It is a top view which shows the electrode assembly of FIG. FIG. 5 is a perspective view showing a portion corresponding to the “A” portion of FIG. 4 in a secondary battery according to another embodiment of the present invention. FIG. 11 is a perspective view showing a state in which the lower surface of the first current collector plate of FIG. 10 faces upward. FIG. 5 is a perspective view showing a portion corresponding to the “A” portion of FIG. 4 in a secondary battery according to still another embodiment of the present invention. FIG. 13 is a perspective view illustrating a state in which the lower surface of the first current collector plate of FIG. 12 faces upward. FIG. 5 is a perspective view showing a portion corresponding to the “A” portion of FIG. 4 in a secondary battery according to still another embodiment of the present invention. FIG. 15 is a cross-sectional view showing a first current collecting plate taken along line 15-15 in FIG.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  1 is a perspective view illustrating a secondary battery according to an embodiment of the present invention, FIG. 2 is a cross-sectional view illustrating the secondary battery of FIG. 1, and FIG. 3 is a cross-sectional view of the secondary battery of FIG. FIG. 4 is an exploded perspective view showing a state before the electrode assembly is wound, and FIG. 4 is a diagram illustrating an electrode assembly of the secondary battery of FIG. 1, first and second current collector plates, first and first FIG. 5 is a partially separated perspective view showing a two-electrode terminal, FIG. 5 is a perspective view showing a state in which the lower surface of the first current collector plate of FIG. 4 is directed upward, and FIG. 6 is a “A” portion of FIG. It is the perspective view which expanded and showed.

  As shown in FIGS. 1 to 3, a secondary battery 100 according to an embodiment of the present invention can be manufactured as a square secondary battery capable of outputting a large capacity, and includes an electrode assembly 110 and an electrode assembly. A first current collector plate 120 and a second current collector plate 130 that are disposed on the solid body 110 and are electrically connected to the electrode assembly 110, the electrode assembly 110, the first current collector plate 120, and the second current collector. A case 140 in which a plate 130 and an electrolytic solution (not shown) are stored, and a cap assembly 150 that closes the upper portion of the case 140 are provided.

  The electrode assembly 110 is formed by winding or stacking a laminated body of a first electrode plate 111, a separator 113, and a second electrode plate 112 formed in a thin plate shape or a film shape. Here, the first electrode plate 111 can function as an anode, and the second electrode plate 112 can function as a cathode. On the other hand, in the embodiment of the present invention, the electrode assembly 110 is positioned inside the case 140 so as to have a vertical winding shaft (or a central axis) C, and the upper portion of the winding shaft C is disposed on the electrode assembly. The upper part of 110 is defined.

  The first electrode plate 111 includes a first electrode current collector 111a and a first electrode active material layer 111b coated on both surfaces of the first electrode current collector 111a. The first electrode current collector 111a is formed with a first electrode uncoated portion 111c that is not coated with the first electrode active material.

The first electrode current collector 111a is made of an aluminum (Al) material in the form of a foil for collecting current, and may be made of other equivalent materials. The first electrode active material layer 111b functions to generate electricity, and may be made of a transition metal oxide (eg, LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ ) or other equivalent material. sell. The first electrode plain portion 111 c is formed at one end of the upper portion of the first electrode current collector 111 a and serves as a current flow path between the first electrode plate 111 and the outside of the first electrode plate 111.

  Specifically, the first electrode plain portion 111c includes a first horizontal portion 114 and a plurality of first protrusions 115. The first horizontal portion 114 and the first plurality of protruding portions 115 can be formed by partially cutting the substantially rectangular first electrode plain portion at a predetermined interval in the length direction. The first horizontal part 114 may have the same length as the length of the first electrode current collector 111a. The plurality of first projecting portions 115 project from the first horizontal portion 114 in the vertical direction. As shown in FIG. 4, the plurality of first protrusions 115 are positioned on one side with respect to the winding shaft C of the electrode assembly 110 while protruding outside the upper end of the electrode assembly 110. It can be divided into a round part R and a flat part P defined by 110 winding shapes. Here, the round portion R is located farther from the winding shaft C of the electrode assembly 110 than the flat portion P, and the plurality of first projecting portions 115 are more than the flat portion P in the winding process of the electrode assembly 110. It is a dense part. And as shown in FIG. 4, each terminal end of the some 1st protrusion part 115 which opposes the winding axis | shaft C of the electrode assembly 110 makes a letter shape. That is, the flat part P has a flat edge perpendicular to the length direction from one side closest to the winding shaft C. Therefore, the plurality of first protrusions 115 are formed such that the width of the first protrusions 115 increases every time the first electrode plate 111 is wound.

  The second electrode plate 112 includes a second electrode current collector 112a and a second electrode active material layer 112b coated on both surfaces of the second electrode current collector 112a. The second electrode current collector 112a is formed with a second electrode uncoated portion 112c that is not coated with the second electrode active material.

  The second electrode current collector 112a may be made of nickel or copper (Cu) in the form of a foil that collects current, or may be made of other equivalent materials. The second electrode active material layer 112b functions to generate electricity, and may be made of, for example, graphite, carbon, or other equivalent material. The second electrode uncoated portion 112 c is formed at one end of the upper portion of the second electrode current collector 112 a and serves as a current flow path between the second electrode plate 112 and the second electrode plate 112.

  Specifically, the second electrode non-coating portion 112c includes a second horizontal portion 116 and a plurality of second projecting portions 117. The second horizontal portion 116 and the plurality of second projecting portions 117 can be formed by partially cutting the substantially rectangular second electrode plain portion from the length direction at a predetermined interval. The second horizontal part 116 may have the same length as the second electrode current collector 112a. The plurality of second projecting portions 117 project from the second horizontal portion 116 in the vertical direction. As shown in FIG. 4, the plurality of second projecting portions 117 project outside the upper end of the electrode assembly 110 while being on the other side (that is, the first projecting portion) with respect to the winding shaft C of the electrode assembly 110. 115, and can be divided into a round part R and a flat part P defined by the winding shape of the electrode assembly 110. Here, the round portion R is located farther from the winding shaft C of the electrode assembly 110 than the flat portion P, and the plurality of second projecting portions 117 are more dense than the flat portion P in the winding process of the electrode assembly 110. It is a part to be done. Each terminal end of the plurality of second projecting portions 117 facing the winding shaft C of the electrode assembly 110 has a single letter shape. That is, the flat part P has a flat edge perpendicular to the length direction from one side closest to the winding shaft C. For this reason, the plurality of protrusions 117 are formed such that the width of the second protrusion 117 increases each time the second electrode plate 112 is wound.

  The first electrode plate 111 and the second electrode plate 112 may be arranged with different polarities.

  The separator 113 is located between the first electrode plate 111 and the second electrode plate 112 to prevent a short circuit and to allow only lithium ion movement, and is a composite of polyethylene, polypropylene, polyethylene and polypropylene. It can be made of film or other equivalent material.

  As described above, the first electrode plate 111 may be aluminum (Al) foil, the second electrode plate 112 may be copper (Cu) foil, and the separator 113 may be polyethylene (PE) or polypropylene (PP). The present invention is not limited to the above materials.

  As shown in FIGS. 3 and 4, the electrode assembly 110 has a first protruding portion 115 of the first electrode plain portion 111 c on one side and the other side of the upper end of the winding electrode assembly 110. The first electrode plate 111, the separator 113, and the second electrode plate 112 are arranged and wound so that the second protruding portion 117 of the second electrode plain portion 112c is exposed. As described above, the electrode assembly 110 may have a stacked configuration in addition to the first electrode plate 111, the separator 113, and the second electrode plate 112 wound up in a vortex.

  A first current collector plate 120 and a second current collector for electrically connecting to the first electrode plate 111 and the second electrode plate 112 are disposed on one side and the other side of the upper portion of the electrode assembly 110, respectively. The electric plate 130 is coupled. That is, the first current collector 120 is coupled to the first side of the upper end of the electrode assembly 110, and the second current collector 130 is opposite to the first side of the upper end of the electrode assembly 110. Coupled to the second side.

  The first current collecting plate 120 is made of a conductive material, and is in contact with the first projecting portion 115 of the first electrode uncoated portion 111c projecting to one side of the upper end of the electrode assembly 110. It is electrically connected to one electrode plate 111. Here, the first current collecting plate 120 may be coupled to the first protrusion 115 of the first electrode plain portion 111c by a laser welding method.

  The second current collector plate 130 is also formed of a conductive material and is in contact with the second projecting portion 117 of the second electrode plain portion 111c that projects to the other side of the upper end of the electrode assembly 110. It is electrically connected to the second electrode plate 112. Here, the second current collector plate 130 may be coupled to the second protrusion 117 of the second electrode plain portion 112c by a laser welding method.

  The first current collector plate 120 and the second current collector plate 130 are coupled to the upper portion of the electrode assembly 110 and are disposed between the electrode terminal located on the upper portion of the electrode assembly 110 and the electrode assembly 110. The current path length can be reduced, and an increase in internal resistance due to an increase in the current path length can be prevented. In addition, the first current collecting plate 120 and the second current collecting plate 130 are directly coupled to the electrode assembly 110 without a separate connection tap, so that a space for the separate connection tap is eliminated inside the case. The number of winding turns of the solid 110 can be increased. Also, the first current collector plate 120 and the second current collector plate 130 are disposed on the electrode assembly 110 and are coupled by a laser welding method to secure a discharge region of gas generated from the inside of the electrode assembly 110. However, the gas can be smoothly discharged from the inside of the electrode assembly 110 to the safety vent located at the top of the electrode assembly 110.

  Next, the structure of the first and second current collecting plates 120 and 130 will be specifically described by taking the structure of the first current collecting plate 120 as an example. The description of the structure of the second current collector plate 130 will be omitted because it corresponds to the structure of the first current collector plate 120.

  As shown in FIGS. 4 to 6, the first current collector plate 120 is formed to include a round region portion Sw that covers the round portion R of the first protrusion 115. In addition, the first current collecting plate 120 may be formed to further include a flat region portion Sc that covers the flat portion P of the first projecting portion 115.

  Specifically, the first current collecting plate 120 may include a base part 121, a flange part 122, a terminal hole 123, and a groove part 124.

  The base 121 is formed of a plate that faces the first protrusion 115 of the electrode assembly 110 and has a planar shape that is substantially the same as the planar shape of the first protrusion 115. That is, the base portion 121 in the round region portion Sw can have a substantially anti-ellipse shape, a semicircle, or another round shape, and the base portion 121 in the flat region portion Sc can have a substantially square shape or other linear shape. .

  The flange portion 122 is formed to extend from the terminal end of the base portion 121 in the direction of the first protrusion 115 of the electrode assembly 110. Here, the flange portion 122 may be formed such that one side close to the winding shaft C of the electrode assembly 110 is opened for smooth coupling between the first current collector plate 120 and the first projecting portion 115. .

  The terminal hole 123 is formed in the flat region portion Sc of the base portion 121 so that a part of the first electrode terminal 152 described later is sandwiched and coupled.

  The groove part 124 is formed in the round area part Sw of the base part 121, and provides a welding space that is implemented for the connection between the first current collector plate 120 and the first projecting part 115. The groove portion 124 is formed such that the base portion 121 projects in the direction of the electrode assembly 110, and the first projecting portion 115 of the first electrode uncoated portion 111 c when the electrode assembly 110 and the first current collector plate 120 are coupled. To form a bent shape. Accordingly, the bottom surface of the groove 124 that is in surface connection with the first protrusion 115 increases the contact area due to surface contact between the first current collector 120 and the first protrusion 115, and the first current collector 120 and the first 1 enables easy attachment (for example, laser welding) with the protrusion 115.

  The second current collecting plate 130 covers the round region portion Sw that covers the round portion R of the second projecting portion 117 and the flat portion P of the second projecting portion 117 so as to correspond to the first current collecting plate 120. The flat region portion Sc may be provided. Specifically, the second current collector plate 130 may include a base part 131, a flange part 132, a terminal hole 133, and a groove part 134. As described above, the second current collector plate 130 corresponds to the configuration of the first current collector plate 120, and thus a detailed description thereof will be omitted.

  The case 140 is formed of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel, and has an opening in which an electrode assembly 110 having a vertical winding shaft C can be inserted and fixed. It consists of a hexahedral shape. In FIG. 1, since the case 140 and the cap assembly 50 are shown in a coupled state, the opening is not shown, but the peripheral portion 140a of the cap assembly 150 is a substantially open portion. is there. Meanwhile, the inner surface of the case 140 is insulated and insulated from the electrode assembly 110 and the cap assembly 150.

  The cap assembly 150 may be coupled to the case 140 and may include a cap plate 151, a first electrode terminal 152 and a second electrode terminal 153, a gasket 154, and a nut 155.

  The cap plate 151 seals the case 140 and may be formed of the same material as the case 140.

  Each of the first electrode terminal 152 and the second electrode terminal 153 passes through the cap plate 151 in an insulated state, and is electrically connected to each of the first current collector plate 120 and the second current collector plate 130. .

  The gasket 154 is formed between each of the first electrode terminal 152 and the second electrode terminal 153 and the cap plate 151, and insulates each of the first electrode terminal 152 and the second electrode terminal 153 from the cap plate 151. . The gasket 154 may have a coupling groove 154a so as to be physically fastened with each of the first electrode terminal 152 and the second electrode terminal 153.

  The nut 155 is fastened along the thread (S) formed on each of the first electrode terminal 152 and the second electrode terminal 153, and each of the first electrode terminal 152 and the second electrode terminal 153 is connected to the cap plate 151. To fix.

  Further, the cap assembly 150 includes a plug 156 that seals the electrolyte injection port after injecting the electrolyte through an electrolyte injection port (not shown) formed in the cap plate 151, and / or the cap plate. A safety vent 157 that is formed at a lower thickness of the 151 and is broken by a set pressure to release gas may be provided.

  In the cap assembly 150 having the above-described configuration, the structure of the first and second electrode terminals 152 and 153 will be described in more detail by taking the structure of the first electrode terminal 152 as an example. . The description of the structure of the second electrode terminal 153 corresponds to the structure of the first electrode terminal 152 and will be omitted.

  The first electrode terminal 152 may include a first head part 152a, a first plate part 152b, a first coupling protrusion 152c, and a first fixing part 152d.

  The first head portion 152 a is formed to penetrate the cap plate 151 and extend to the top of the cap plate 151. The first head portion 152 a has a thread (S) formed on the outer surface for fastening with the nut 155.

  The first plate portion 152b is connected perpendicularly to the first head portion 152a, and is positioned below the cap plate 151.

  The first coupling protrusion 152c protrudes from one side of the first plate 152b and is coupled to the coupling groove 154a of the gasket 154. The coupling between the first coupling protrusion 152c and the coupling groove 154a prevents the first electrode terminal 152 from rotating during the manufacturing process of the secondary battery.

  The fixing part 152d is formed by extending an extension part (52d in FIG. 4) extending from the lower part of the first plate part 152b through the terminal hole 123 of the first current collector 120 and deforming it by a rivet process. Is done. That is, the fixing portion 152 d has a larger area than the terminal hole 123 of the first current collector plate 120 in the lower portion of the first current collector plate 120. Thereby, the fixing portion 152d functions to fix the first electrode terminal 152 to the first current collector plate 120. On the other hand, although not shown, a plurality of fixing portions 152d may be formed below the first plate portion 152b. In this case, the coupling strength between the first electrode terminal 152 and the first current collector plate 120 can be further improved. Here, when a plurality of fixing portions 152d are formed, of course, a plurality of terminal holes 123 of the first current collector plate 120 are also formed.

  The second electrode terminal 153 may include a second head part 153a, a second plate part 153b, a second coupling protrusion 153c, and a second fixing part 153d. As described above, the second electrode terminal 153 corresponds to the configuration of the first electrode terminal 152, and a detailed description thereof will be omitted.

  The electrode assembly 110 having the above-described configuration passes through the opened upper portion of the case 140 and is inserted and coupled into the case 140 to be injected with an electrolytic solution, and the cap assembly 150 is opened. The secondary battery is completed by covering and sealing the upper part.

  On the other hand, in one embodiment of the present invention, it is indicated that the terminal ends of the first and second projecting portions 115 and 117 facing the winding shaft C of the electrode assembly 110 form a single letter. However, as shown in FIG. 7, the terminal ends of the first and second protrusions 215 and 217 where the electrode assembly 210 faces the winding shaft C of the electrode assembly 210 are the winding shafts of the electrode assembly 210. It can be formed to have a V shape protruding in the direction of C. That is, the flat part P has a flat edge that is inclined from the length direction toward the central region of the electrode assembly 210. Further, as shown in FIG. 8, the terminal ends of the first and second protrusions 315 and 317 where the electrode assembly 310 faces the winding shaft C of the electrode assembly 310 are separated from the winding shaft C of the electrode assembly 310. It can be formed to have a V-shape recessed in the lateral direction. Here, the V-shape is far away from the winding shaft C. That is, the flat portion P has a flat edge that is inclined from the length direction toward the central region of the electrode assembly 310.

  Here, the conditions for forming the electrode assembly 110 of FIG. 4, the electrode assembly 210 of FIG. 7, and the electrode assembly 310 of FIG. 8 are given as examples of conditions for forming the electrode assembly 310 of FIG. This is as follows.

  As shown in FIG. 9, the conditions for forming the electrode assembly 310 are as follows. First, 0 <L1 and L2 <D / 2 (L1 and L2: flat portions of the first and second protrusions 315 and 317, respectively. P length, D: overall length of the flat part of the electrode assembly), and secondly, 0 <L1 + L2 <D. Here, the reason why L1 and L2 are set to be smaller than D / 2 is that when L1 and L2 are larger than D / 2, the first protrusion 315 and the second protrusion 317 are formed on the plane of the electrode assembly 310. This is because the lengths can be increased and overlap each other. In this case, an electrical short circuit can occur. The reason why L1 + L2 is set to be smaller than D is that the first protrusion 315 and the second protrusion 315 are not overlapped with each other, and the respective round portions R regions of the first and second protrusions 315 and 317 are set. This is to ensure.

  As described above, the secondary battery 100 according to the embodiment of the present invention includes the first current collecting plate 120 and the second current collecting plate 130 in the upper part of the electrode assembly 110 having the vertical winding shaft C. And the first electrode terminal 152 and the second electrode terminal 153 located on the upper part of the electrode assembly 110. Accordingly, the secondary battery 100 according to the embodiment of the present invention can be used when the current collector plate is coupled to each of the upper and lower portions of the electrode assembly having the vertical winding shaft and the horizontal winding. The current path length between the electrode assembly and the electrode terminal can be reduced as compared with the case where the current collector plates are coupled to both sides of the electrode assembly having the shaft. Therefore, the secondary battery 100 according to the embodiment of the present invention can increase the output of the battery by reducing the internal resistance that increases as the current path length increases.

  In addition, in the secondary battery 100 according to the embodiment of the present invention, the first current collecting plate 120 and the second current collecting plate 130 are directly coupled to the electrode assembly 110 without a separate connection tap. Accordingly, the secondary battery 100 according to the embodiment of the present invention reduces the space occupied by the separate connection tap in the case 140 and increases the number of winding turns of the electrode assembly 110 by the reduced space. be able to. Therefore, the secondary battery 100 according to the embodiment of the present invention can increase the capacity of the battery.

  In addition, the secondary battery 100 according to an embodiment of the present invention includes an upper part of the electrode assembly 110 having a vertical winding shaft C by laser welding a first current collecting plate 120 and a second current collecting plate 130. The first electrode uncoated region 111c and the second electrode uncoated region 112c are coupled to each other. As a result, the secondary battery 100 according to the embodiment of the present invention collects the anode uncoated region and the cathode uncoated region into the anode uncoated region and the cathode uncoated region by ultrasonic welding in a state where the anode uncoated region and the cathode uncoated region are pressed together. When the electric plates are coupled, it is possible to prevent a phenomenon in which the gas emission region generated from the inside of the electrode assembly is reduced. In addition, in the secondary battery 100 according to the embodiment of the present invention, a current collector plate is coupled to each of the anode uncoated portion and the cathode uncoated portion exposed on both sides of an electrode assembly having an existing horizontal winding shaft. In this case, it is possible to prevent the phenomenon that the gas released from the inside of the electrode assembly hits both sides of the case and does not easily reach the safety vent located at the top of the electrode assembly. Therefore, the secondary battery 100 according to the embodiment of the present invention can improve the safety of the battery.

  Next, a secondary battery according to another embodiment of the present invention will be described.

  The secondary battery according to another embodiment of the present invention has the same configuration as that of the secondary battery 100 according to the embodiment of the present invention, except that only the configuration of the groove formed in the current collector plate is different. And perform the same function. Thereby, the duplicate description with respect to the same structure is abbreviate | omitted, and demonstrates the structure of the 1st current collecting plate 420 as an example about the structure of a current collecting plate.

  FIG. 10 is a perspective view illustrating a portion corresponding to the portion “A” of FIG. 4 of a secondary battery according to another embodiment of the present invention, and FIG. 11 is a diagram of the first current collector plate of FIG. It is a perspective view which shows the state which the lower surface faced up.

  As shown in FIGS. 10 and 11, the first current collector plate 420 is formed to include a round region portion Sw that covers the round portion R of the first protrusion 115. In addition, the first current collector plate 420 may be formed to further include a flat region Sc that covers the flat portion P of the first protrusion 115.

  Specifically, the first current collector plate 420 may include a base part 421, a flange part 422, a terminal hole 423, and a plurality of groove parts 424.

  The base part 421, the flange part 422, and the terminal hole 423 are the same as the base part 121, the flange part 122, and the terminal hole 123 of the first current collector plate 120 shown in FIG.

  The groove portion 424 performs the same function as the groove portion 124 of the first current collector plate 120 shown in FIG. 6 except that the groove portion 124 is formed in a single groove shape in the round region portion Sw. There is a difference in that a plurality of portions are formed in the horizontal direction parallel to the length direction of the first current collector plate 420 in the portion Sw. Such a groove 424 intersects with the protrusion 115 positioned in the round region Sw on a plane.

  As described above, the secondary battery according to another exemplary embodiment of the present invention includes the plurality of grooves 424 formed in the horizontal direction in the round region portion Sw of the first current collector plate 420, thereby implementing the groove 424. The coupling strength between the first current collector plate 420 and the projecting portion 115 can be increased by intersecting the projecting portion 115 with the laser welding line formed by the laser welding performed.

  Next, a secondary battery according to still another embodiment of the present invention will be described.

  A secondary battery according to still another embodiment of the present invention differs from the secondary battery 100 according to an embodiment of the present invention only in the configuration of the groove formed in the current collector plate and has the same configuration. And perform the same function. Thereby, the duplicate description with respect to the same structure is abbreviate | omitted, and demonstrates the structure of the 1st current collecting plate 520 as an example about the structure of a current collecting plate.

  12 is a perspective view showing a portion corresponding to the portion “A” of FIG. 4 in a secondary battery according to still another embodiment of the present invention, and FIG. 13 is a first current collector plate of FIG. It is a perspective view which shows the state which faced the upper surface of the top.

  As shown in FIGS. 12 and 13, the first current collector plate 520 is formed to include a round region portion Sw that covers the round portion R of the first protrusion 115. In addition, the first current collector plate 520 may be formed to further include a flat region portion Sc that covers the flat portion P of the first protrusion 115.

  Specifically, the first current collector plate 520 may include a base portion 521, a flange portion 522, a terminal hole 523, and a plurality of groove portions 524.

  The base portion 521, the flange portion 522, and the terminal hole 523 are the same as the base portion 121, the flange portion 122, and the terminal hole 123 of the first current collector plate 120 shown in FIG.

  The groove portion 524 performs the same function as the groove portion 124 of the first current collector plate 120 shown in FIG. 6 except that the groove portion 124 of the first current collector plate 120 is formed in a single groove shape in the round region portion Sw. Differently, there is a difference in that a plurality of round current sections Sw are formed in a vertical direction perpendicular to the length direction of the first current collector plate 420. Such a groove portion 524 can specifically designate a laser irradiation position at the time of laser welding so that laser welding can be performed at a more accurate position.

  As described above, the secondary battery according to another exemplary embodiment of the present invention includes the plurality of groove portions 524 formed in the vertical direction in the round region portion Sw of the first current collector plate 520 so that laser welding can be performed. It is possible to improve the welding efficiency by being performed at a more accurate position.

  Next, a secondary battery according to still another embodiment of the present invention will be described.

  A secondary battery according to another embodiment of the present invention differs from the secondary battery 100 according to an embodiment of the present invention only in a configuration in which an opening (or a slit) is further formed in the current collector plate. Only have the same configuration and perform the same function. Thereby, the duplicate description about the same structure is abbreviate | omitted, and demonstrates the structure of the 1st current collecting plate 620 as an example about the structure of a current collecting plate.

  14 is a perspective view illustrating a portion corresponding to the portion “A” in FIG. 4 of a secondary battery according to still another embodiment of the present invention. FIG. 15 is a line 15-15 (level) in FIG. It is sectional drawing which shows the 1st current collecting plate which follows).

  As shown in FIGS. 14 and 15, the first current collector plate 620 is formed to include a round region portion Sw that covers the round portion R of the first protrusion 115. Further, it may be formed to further include a flat region portion Sc that covers the flat portion P of the first projecting portion 115.

  Specifically, the first current collector plate 620 may include a base part 621, a flange part 622, a terminal hole 623, a groove part 624, and a plurality of slits 625.

  The base part 621, the flange part 622, the terminal hole 623, and the groove part 624 are the same as the base part 121, the flange part 122, the terminal hole 123, and the groove part 124 of the first current collecting plate 120 shown in FIG.

  The slit 625 is formed so as to penetrate the region of the groove 624, so that the operator can densely seal the first protrusion 115 outside the electrode assembly 110, and laser weld the groove 624 and the first protrusion 115. Be able to grasp the condition. In addition, the slit 625 blocks or reduces the transmission of laser heat applied to one side of the slit 625 to the other side of the slit 625 during laser welding of the groove 624 and the first projecting portion 115. Laser welding can be concentrated in welding 624 and the first protrusion 115. Thereby, the laser welding efficiency of the groove part 624 and the 1st protrusion part 115 can increase.

  As described above, the rechargeable battery according to another exemplary embodiment of the present invention includes the slits 625 formed in the groove 624 of the first current collector plate 620, thereby providing a dense state of the first protrusions 115. When a defect occurs in the welded state between the groove 624 and the first protrusion 115, the operator can deal with the defect.

  Further, the secondary battery according to still another embodiment of the present invention can concentrate the laser heat by welding the groove 624 and the first protrusion 115 by laser welding through the slit 625. Accordingly, in the secondary battery according to another exemplary embodiment of the present invention, the laser welding efficiency between the groove 624 and the first protrusion 115 is increased, and the first current collector plate 620 and the electrode assembly 110 are coupled to each other. Reliability can be increased.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 100 Secondary battery 110 Electrode assembly 120 1st electrical power collector 130 2nd electrical power collector 140 Case 150 Cap assembly

Claims (16)

A first electrode plate having a plurality of first protrusions extending from one end; and a second electrode plate having a plurality of second protrusions extending from the one end, the plurality of first protrusions or the plurality of first protrusions. An electrode assembly formed such that at least one of the two protruding portions includes a flat portion and a round portion;
A case for housing the electrode assembly;
A secondary battery comprising: a current collector plate connected to at least one of the plurality of first protrusions or the plurality of second protrusions and covering at least the round part. The flat portion extends in the length direction of the electrode assembly,
The round part is located on one side of the terminal end of the electrode assembly from the central axis of the electrode assembly;
The secondary battery according to claim 1, wherein the current collector plate is welded to the round part.   The secondary battery according to claim 2, wherein the flat portion has a flat edge perpendicular to a length direction from one side closest to the central axis.   The secondary battery according to claim 2, wherein the flat portion has a flat edge inclined from the length direction toward a central region of the electrode assembly.   The current collector plate includes a flat region portion at a position corresponding to the flat portion of the electrode assembly, and a round region portion welded to the round portion of the electrode assembly. Secondary battery. The current collector plate is a first current collector plate connected to the plurality of first protrusions from a first side of one end of the electrode assembly,
3. The second current collector plate according to claim 2, further comprising a second current collector plate connected to the plurality of second protrusions from a second side opposite to the first side of one end of the electrode assembly. Secondary battery.   The secondary battery according to claim 2, wherein the current collector plate includes a groove portion, and is welded to the electrode assembly at the groove portion.   The secondary battery according to claim 7, wherein the groove portion of the current collector plate pressurizes and / or bends at least one of the plurality of first protrusions or the plurality of second protrusions.   The secondary battery according to claim 7, wherein the current collector plate further includes a base portion including the groove portion and a flange portion surrounding the base portion.   The secondary battery according to claim 7, wherein the groove portion of the current collector plate includes a plurality of groove portions extending in a length direction and is welded to the electrode assembly.   The secondary battery according to claim 7, wherein the groove portion of the current collector plate includes a plurality of groove portions extending in a direction perpendicular to the length direction, and is welded to the electrode assembly.   The secondary battery according to claim 7, wherein the current collector plate has at least one opening formed through the groove.   The secondary battery according to claim 12, wherein the at least one opening includes a plurality of slits.   The secondary battery according to claim 1, wherein one end of the electrode assembly is not coated with an electrode active material.   15. The cap assembly according to claim 1, further comprising: a cap plate that seals the opening of the case; and a cap assembly that includes a safety vent formed to remove gas from the secondary battery. A secondary battery according to item. The said current collecting plate is laser-welded to at least any one of the said some 1st protrusion part or the some 2nd protrusion part, The 2 of any one of Claims 1-15 characterized by the above-mentioned. Next battery.

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